If you run WVO or SVO it is imperative that you start up and shut down on straight diesel. The only way to assure that will happen is two seperate tanks and essentially seperate fuel systems; diesel to start and shut down VO to run. Failure to do this can produce early engine failure. If you just mix the two in a single tank it will seperate into two layers. Your truck will be running on which ever layer is at the tank pickup at any particular moment. If it happens to be the VO layer when you shut down there is a very good chance you will have a lot of trouble getting it started again.

You need to ask a VO expert about using VO the sponser of this forum is Lesk WVO conversions. they have a link at the top of this thread. You can also get hold of them by starting a new thread titled "Questions for Lesk WVO"